621
FXUS62 KRAH 200019
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
819 PM EDT Sat Apr 19 2025

.SYNOPSIS...
Warm, sub-tropical high pressure will extend from near Bermuda to
the South Atlantic states through the weekend. Meanwhile, a cold
front will approach from the northwest and move south through VA
Sunday morning. The front will then move into and briefly stall over
northern NC Sunday afternoon and night, then return north across the
Middle Atlantic as a warm front on Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 819 PM Saturday...

Mid evening water vapor imagery reveals high pressure off the
Southeast coast, with abundant mid/high clouds across the OH and MS
Valley`s. A surface ridge was positioned well off the NC coast, with
a cold front draped from western NY through portions of KY.
Convection along the front is remaining well north of our area, and
will not be a factor in tonight`s forecast. Temperatures across the
region reached the mid to upper 80s today, but have already
retreated into the low to mid 70s.

For the rest of tonight, expect a continued infusion of mid/high
clouds across the area given southwesterly flow aloft. The warm
daytime temperatures, combined with increased cloud cover and about
3-5 kts of wind, will result in a mild night. Lows will generally
range from the lower 60s in the north to the mid 60s in the south,
which is about 2 to 3 degrees warmer than what was seen this
morning.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
As of 355 PM Saturday...

* Continued unseasonably warm

A mid/upr-level cyclone now over the Southwest will pivot into the
TX panhandle vicinity by 12Z Sun, then lift newd across the cntl
Plains and upr MS Valley through the end of the forecast period,
while deepening. Downstream, and on the nwrn through nrn periphery
of a mid/upr-level anticyclone forecast to linger off the South
Atlantic coast, a ridge will progress across and offshore the Middle
Atlantic. As the ridge progresses across and east of cntl NC,
mid/upr-level flow will back to swly and strengthen amid weakly
falling heights, with an associated thickening of a plume of cirrus
and cirrostratus.

At the surface, warm, sub-tropical high pressure will continue to
extend wwd across the South Atlantic states. Meanwhile, a cold front
will move in backdoor fashion swwd across srn VA and nrn NC Sun
afternoon-evening, then stall along an arc from near ROA to RWI to
HSE Sun night.

It will be continued very warm in cntl NC Sun, but with less breezy
and gusty sswly surface winds within a lessening MSL pressure
gradient ahead of the approaching back door cold front and with near
persistence high temperatures mostly 83-88 F, despite the
aforementioned veil of considerable high clouds. Surface convergence
along the front will focus a tongue and relative maximum of surface
dewpoints in the lwr 60s F, and a related weak instability axis of
500-1000 J/kg of MLCAPE. Point forecast soundings indicate much of
that buoyancy will be capped by the lingering influence of the EML
now maximized over the srn Middle Atlantic/Carolinas. An associated
area of relatively more-concentrated (scattered) and locally deeper
cumulus will probably result, but any weak updrafts that breach the
cap will be hindered and opposed by both dry entrainment and a lack
of any deeper lift/forcing mechanism amid the passing ridge aloft.
Any associated "pinhead", light shower or sprinkle should be too
short-lived and isolated to warrant mentionable measurable PoP.

Point forecast soundings also indicate the backdoor front may be
accompanied by a several hour period of nely surface winds up to 15-
20 kts in gusts immediately following its passage, mainly during the
evening over the far ne Piedmont and nrn Coastal Plain. An area of
post-frontal ceilings around 1000 ft AGL will also likely develop
from nern NC and particularly points nwd into cntl VA Sun night-Mon
morning. Low temperatures should be mainly upr 50s to lwr 60s.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 321 PM Saturday...

The mid-level ridge will begin to breakdown Monday into Tuesday, as
a strong upper trough lifts through the Great Lakes region. A series
of weak short-waves will traverse overhead the rest of the week.
Models hint at another Great Lakes trough and associated embedded
mid-level perturbations advecting across the eastern seaboard Friday
into the weekend.

At the sfc, strong pre-frontal swly flow on Monday will promote
another day of temps reaching the mid 80s.  Dew points will
generally hover in the mid 50s, as anomalous PWAT remains largely to
our northwest.  Given little upper or sfc forcing, Monday should
remain mostly dry. As we pivot to the overnight, however, the
influence of the upper trough and associated moisture flux will
start to inch closer to our area. Will maintain a dry forecast
through 12Z Tuesday for now, but would not be surprised if some
showers reach the northwest Piedmont in the early Tuesday morning
hours.

While the strong upper forcing will generally remain well north of
our area Tuesday, sfc convergence along an advancing front, combined
with increasing moisture flux will promote shower/thunderstorm
chances across central NC. Expect a diurnal maxima in showers/tstorm
coverage with highest POPs Tuesday afternoon.  Bulk-layer shear will
generally trend downwards with time Tuesday, but some afternoon
lingering shear of 20 to 30 kts could coincide with the diurnal
maxima of tstorms to promote perhaps a stronger storm or two.
Overall though, the severe risk seems limited given the
aforementioned lack of upper forcing.

Anomalous moisture will linger through the rest of the extended, as
the sfc front shifts south of us, stalls, and the rides north as a
warm front by Friday. Weak perturbations will traverse overhead each
day, promoting continued diurnal chances for showers and storms each
day.  A few stronger storms could be possible Wednesday
afternoon/evening as a weak short-wave and associated pocket of
moderately stronger shear moves over. Otherwise, severe weather is
not expected through at least Friday.

As the next trough ejects across the Great Lakes, a bit better
shear/upper forcing may extend south over central NC on Saturday.
However, some ensemble output only extends this stronger shear down
into VA. Regardless, expect wet conditions to continue into the
weekend.

Temperatures will be warm over this period, generally in the lower
to mid 80s, with perhaps some relative reprieve into the upper 70s
across the NC/VA border.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
As of 715 PM Saturday...

24 hour TAF period: VFR conditions are expected through the next 24
hours. Scattered to broken high clouds are expected throughout the
entire period. While FAY will likely have a ceiling for some of the
next 24 hours, chose not to carry a ceiling there with greater cloud
cover expected to the north. Cannot rule out an isolated gust at the
very beginning of the TAF period, but otherwise the wind should
remain sustained between 5-10 kt.

Outlook: A backdoor cold front will be accompanied by a band of post-
frontal, IFR-MVFR ceilings over sern VA and nern NC late Sun-Sun
night, some of which may advance to near and especially just
northeast of RWI Sun night-Mon morning. A several hour period of
nely surface winds up to 15-20 kts in gusts will also be possible
immediately following the passage of the front, which will also be
most likely at RWI, during the evening Sun. A front and next chance
of convection and flight restrictions will settle over NC Tue-Wed.

&&

.CLIMATE...
Record High Temperatures:

April 19:
KGSO: 92/1917
KRDU: 93/1941
KFAY: 94/1941

April 20:
KGSO: 94/1917
KRDU: 93/1896
KFAY: 94/1917

Record High Minimum Temperatures:

April 20:
KGSO: 65/1941
KRDU: 67/1896
KFAY: 69/2011

April 21:
KGSO: 64/1927
KRDU: 70/1896
KFAY: 68/2017

April 22:
KGSO: 63/1967
KRDU: 66/1909
KFAY: 64/1963

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...MWS
NEAR TERM...Leins
SHORT TERM...MWS
LONG TERM...Luchetti
AVIATION...Green/MWS
CLIMATE...RAH